Property and Equipment (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Property and equipment
Property and equipment, gross	$ 9,515,000		$ 9,515,000		$ 8,738,000
Less accumulated depreciation and amortization	(6,607,000)		(6,607,000)		(6,290,000)
Property and equipment, net	2,908,000		2,908,000		2,448,000
Depreciation expense	160,000	$ 176,000	317,000	$ 345,000
Computer Equipment
Property and equipment
Property and equipment, gross	992,000		992,000		862,000
Software
Property and equipment
Property and equipment, gross	333,000		333,000		254,000
Lab Equipment and Furniture
Property and equipment
Property and equipment, gross	5,603,000		5,603,000		5,194,000
Leasehold Improvements
Property and equipment
Property and equipment, gross	$ 2,587,000		$ 2,587,000		$ 2,428,000